Glass yarn having controlled torsional forces



March 4, 1969 c, DUDZlK ET AL 3,430,432

GLASS YARN HAVING CONTROLLED TORSIONAL FORCES Original Filed July 23, 1964 Sheet of 2 Fig.2 f? bwenlbrs CYIeSteP J; Dudzik Gig E Perkins aw/ 0m March 4, 1969 c. J. DUDZIK ET AL GLASS YARN HAVING CONTROLLED TORSIONAL FORCES Sheet Original Filed July 23, 1964 InVenibBS. czestep J. Dudzik G2 1 E. Perkins United States Patent Ofiice 3,430,432 Patented Mar. 4, 1969 3,430,432 GLASS YARN HAVING CONTROLLED TORSIONAL FORCES Chester J. Dudzik and Guy E. Perkins, Warwick, R.I.,

assignors to Leesona Corporation, Warwick, R.I., a corporation of Massachusetts Original application July 23, 1964, Ser. No. 384,595, now Patent No. 3,348,368, dated Oct. 24, 1967. Divided and this application Aug. 7, 1967, Ser. No. 658,867 U.S. Cl. 57-140 2 Claims Int. Cl. D02g 1/06, 3/18 ABSTRACT OF THE DISCLOSURE Glass yarn which has been textured to provide therein characteristics of permanent crimp, high stretch and recovery characteristics, and fiexibility and strength.

This application is a division of copending application Ser. No. 384,595 filed July 23, 1964, now U.S. Patent No. 3,348,368.

The present invention relates to the manufacture of glass yarn and relates, more particularly, to high speed continuous processing of glass yarn to impart crimp and/ or torque therein in order that the yarn may be made into an article exhibiting permanent crimped, wavy or fiuffed characteristics.

In United States Patent 2,803,108 to N. J. Stoddard et al., issued Aug. 20, 1957 there are disclosed and claimed methods of processing polyamide and other thermoplastic textile yarns. These methods contemplate, broadly, passing yarn through a heated zone to heat the yarn to a precribed temperature, cooling the yarn to stabilize the same after passage through the heated zone, and winding up the processed yarn. It is within the scope of the cited patent to twist the yarn during processing to impart certain physical characteristics thereto such as that which may generally be called stretch. Broadly stated, the yarn which displays these characteristics may be thought of as exhibiting a number of crimps and/or pigtails when the yarn strand is relaxed, i.e., when little or no tension is present in the yarn. The crimps are simply undulations or wavy formations in the yarn. The pigtails are actually sections of the individual yarn filaments comprising the yarn strand which are looped and twisted about themselves. Obviously, the pigtails so formed will have one or more loops or cross-over points therein where a filament has spiraled or twisted about itself. When the processed yarn is placed under higher tension the loops in the filaments uncoil to permit the yarn strand to extend and when the higher tension is relieved the crimps and pigtails reform to contract the length of the yarn. This process is continuously reversible if the yarn has been permanently set in accordance with the methods of the cited patent.

Prior to the present invention it has been impractical from a commercial standpoint to process filament glass yarn in the manner just recited for processing polyamide yarn. While it is true that glass yarn under proper conditions of correlated temperature and tension can be false twisted in order to impart stretch characteristics thereto, it has been found that, with prior art methods these stretch characteristics in the yarn were both difficult to achieve and retain. It has been discovered that glass yarn which was processed by the prior art methods lost virtually all its strength and recovery characteristics due to its being bent and abraded as occurs when the yarn is passed through a false twist spindle, or when the false twisted glass yarn is stretched and relaxed. This is largely due to the poor abrasion characteristics of the individual filaments of the glass yarn after the yarn has been heated. That is to say, when filament glass is manufactured it is provided normally with a finish, such as a lubricant, which forms a protective coating providing the filaments with increased abrasion resistance. When this yarn is subsequently passed through a heat zone to reform the yarn, as contemplated by the present invention, the finish is burned off or its abrasion resistance is reduced. Thus, the yarn is thereafter responsive to abrasion as adjacent sections of the filaments rub on each other as the yarn is bent about a small radius so that the yarn cracks or fractures thereby destroying the continuity of the crimps and pigtails which, as explained, actually account for the stretch characteristics of the yarn. To consider further the condition of the yarn passing through the false twist spindle it will, of course, be appreciated that the individual filaments comprising the glass yarn strand are subjected to considerable rubbing on one another or, in other words, interfiber friction takes place as the yarn is wrapped around the twist trapping member of the spindle. In the absence of lubrication, these filaments abrade and subsequently fracture. Similarly, when the glass yarn which has been false twisted is alternately stretched and relaxed the pigtails uncoil and recoil thereby subjecting them to interfiber friction and considerable abrading at the cross-over points of the pigtails, all of which leads to fracturing of the filaments if the yarn is unlubricated.

With the foregoing in mind it has been found that in practice with the present invention it is possible to process filament glass yarn in a continuous process where the glass yarn which is subsequently formed into fabrics or other articles exhibits permanent qualities of stretch. Briefly, the present invention is directed to methods and apparatus for processing glass yarn wherein the yarn is continuously drawn from a source of supply, the yarn is twisted whereafter it is passed through a heat zone at a selected linear speed under uniform tension to heat the yarn and set it in its twisted formation, the yarn is then cooled and lubricated prior to entering the false twist spindle. After being untwisted it is collected and the torsional forces in the yarn are controlled. The torsional forces may be controlled by applying a soluble stiffening agent to the yarn prior to collecting the yarn, or by heating the yarn a second time under uniform tension conditions. The processed yarn may be subsequently formed into a fabric with the torsional forces in the yarn controlled. If a stiffening material has been used it can subsequently be washed out. The weave or formation of the fabric or article formed therefrom will thereupon serve to restrict the coiling or pigtailing of the filaments of the yarn to the end that a fabric exhibiting permanent stretch characteristics is obtained.

For a fuller understanding of the nature and objects of the invention reference should be made to the following detailed description taken in connection with the accompanying drawing wherein:

FIG. 1 is a diagrammatic side sectional view of a multi-station apparatus adapted to practice the present invention;

FIG. 2 is a diagrammatic front elevational view of the apparatus of FIG. 1; and

FIGS. 3 and 4 are fragmentary views similar to FIG. 1 showing modifications within the scope of the present invention.

With reference to the drawing, a preferred apparatus for carrying out the present invention comprises a multistation machine, each station including a false twist spindle, a separate yarn supply, a wind up means, a first heat zone for heating the glass yarn to a plastic state while the yarn is in a twisted condition, a lubricating station for applying a lubricant to the yarn while the yarn is in its twisted condition, a sizing station for applying a size to the yarn after the yarn has been untwisted, a second heat zone for setting the size prior to winding up of the processed yarn and a tension device for maintaining the yarn in a tensioned condition during its passing through said first heat zone, lubricating station, false twist spindle, sizing station, and second heat zone. The take up is coordinated by conventional drive means, not shown, to correlate the linear speed of travel of the glass yarn with the rotational speed of the false twist spindle to insert the desired false twist into the yarn. The temperatures of the heat zones are likewise correlated to the linear speed of travel and count of the yarn to supply suflicient heat thereto whereby in the first heat zone the glass yarn is transformed to a plastic state to effect the proper yarn setting in the twisted formation. The second heat zone is similarly correlated in order to properly heat the yarn with the size thereon in order that the size may be fixed or dried prior to take-up of the yarn.

With attention now to the drawing there is illustrated one processing station. It will be understood that in the preferred apparatus a plurality of similar stations would be arranged in side by side relationship along a common frame, all of the stations being operated from a single source of driving power. It will be further understood since all of these stations would be similar in construction it will sufiice to describe but one of the stations in the following description. In the present instance the glass yarn is supplied from a supply package mounted at the base of the machine for over-end delivery through a pigtail guide 12 and over a guide rod 14 to tension means 16. Tension means 16 may be of the interdigitated finger type presenting a tortuous course to the yarn Y. A pair of pigtail yarn guides 17 and 18 are disposed on opposite sides of tension 16 in order to guide the yarn in a straight line path through this tension means. The yarn Y is directed from pigtail guide 18 upwardly through a further pigtail guide 19 positioned in vertical alignment with and spaced below a heater 20. Pigtail guide 19 serves to facilitate movement of the yarn into an appropriate tube 22 of heater 20. Heater 20 may be any conventional type such as the electrically controlled type disclosed and claimed in US. Patent 2,864,931 to N. I. Stoddard et al., entitled Heating Device for Use in Processing Textile Yarns, issued Dec. 16, 1958 and operated by conventional means not shown herein to accurately regulate the amount of heat imparted to the yarn during its travel therethrough. While it is not the intention of the present invention to limit the method to a specific type of heating it should be noted, in practice with the instant invention, that it is desirable for the heater to be of the radiant type so that the strand of yarn Y is not in direct contact with any element of the heater. Rather, as illustrated, the yarn is conducted axially through the heated tube 22 forming a radiant yarn heating zone centrally through the heater 20. Preferably tube 22 is approximately 27 inches long and is capable of being heated in the order of 700-25 00 F. by heater 20.

From the heater 20 the yarn passes upwardly through a centering guide 26 to a false twist spindle 28, said spindle 28 being spaced sufficiently from the heater to provide a cooling zone for the yarn therebetween. The guide 19 cooperates with guide 26 to direct the yarn axially through tube 22 while keeping the yarn from running against the wall of the tube. Centering guide 26 also centers or positions the yarn for entrance into the central bore of false twist spindle 28 of the type, for example, disclosed and claimed in U.S. Patent 2,829,487 to NJ. Stoddard et al., entitled Yarn Spindle, issued Apr. 8, 1958. As the yarn moves in its path from heater 20 to spindle 28 the yarn is caused to run against a lubricant applying roll 30 mounted for rotation on a shaft 32 which is driven by a suitable power source, not herein shown. As shown in FIGS. 1 and 2 the roller has its lower section immersed in a trough 34 holding a lubricating bath 36 of suitable material. Thus, prior to entering the false twist spindle 28, the yarn has a lubricant applied to the surface thereof.

The false twist spindle 28 is of the high speed beltdriven type and operates in the well-known manner to impart a high degree of twist to the yarn Y. The twist imarted to the yarn by the false twist spindle 28 extends in the yarn from the spindle 28 downwardly through heater 20 to tension 16 which performs the additional function of preventing the twist in the yarn from extending beyond said tension 16. Thus, it will be seen that the yarn, as it is guided against roller 30, is in a twisted condition. Moreover, it will be appreciated that as the yarn extends through tube 22 of heater 20 it is also in a twisted state. Advantageously, spindle 28 includes a spindle blade 38 having a central bore or aperture therethrough, said blade being in driving contact with an elongated belt 40. An idler pulley 42 which is one of a series of such pulleys along the apparatus, serves to track the driving belt. The driving belt 40 is operated from a power source not herein shown. The upper end of spindle blade 38 is formed as an enlarged spindle head 44 which is centrally apertured in coaxial alignment with the aperture through the main spindle blade to accommodate the yarn axially therethrough. A twist trapping device spans the opening across the center of spindle head 44 and, in operation, the yarn is wrapped around this twist trapping device in order that yarn may be suitably twisted.

As the yarn emerges upwardly from twist trapping device 46 it is guided through a guide 48 which centers the yarn over device 46. The yarn passes from device 46 to guide bar 49 and then through a pigtail guide 50 and in doing so the yarn is caused to contact a further roller 51. Said roller 51 is mounted on a power driven shaft 52 whereby, as said shaft 52 is rotated, the roller 51 is caused to rotate at a predetermined surface speed related to the linear speed of the yarn. It will be appreciated that roller 51 may also serve as a furnishing device. As seen in FIGS. 1 and 2 roller 51 is partially submerged in a trough 54 containing a bath 56 of a sizing agent.

Thus, as the yarn Y passes around roller 51 which is immersed in the bath 56 the yarn takes on size from the bath. It will be apparent that vertical adjustment of bar 49 and guide 50 relative to the axis of shaft 52 will also control the degree of contact of the yarn with roller 51 and, thereby control the amount of pick-up of size by the yarn.

There is disposed upwardly of said sizing station a further heater 60 having a centrally positioned elongated tube 61 therein which is located to receive the yarn axially therethrough upon its passage through guide 50. Heater 60 is preferably about 27 inches long and is capable of being heated to a temperature to fix or dry the size on the yarn strand. Heater 60 may be of any suitable type but, preferably is a radiant heater such as that fully disclosed in the earlier cited Patent 2,864,931. By this construction the heater is not contaminated with the sizing agent, that is to say, the sizing agent is not deposited on the radiant heater. Thus the operating efliciency of the apparatus is maintained to a higher degree by the use of a radiant heater. From heater 60 the yarn is directed through a guide 62 to a take-up means. Said take-up means is constituted as a pair of rolls 65 and 66. Roll 66 is powered through shaft 68 upon which this roll is mounted and, in turn, roll 65 is driven by frictional contact with roll 66. A traverse 70 is arranged to receive the yarn directed thereto from guide 62 and over guide bar 63 in order to deposit the yarn in a level wind on roll 65. It will be appreciated that the yarn is under a uniform predetermined tension at all times between its passage from tension 16 to take-up 65, the level of tension between any two contact points being, of course, dependent upon the conditions of the contact points, sizing material, yarn count, lubricant, etc. Moreover, by virtue of the take-up arrangement the yarn is taken up at a predetermined rate correlated with the tension condition in the strand as it is processed through the apparatus described.

Referring now more particularly to the lubricating material employed in lubricating bath 36 in practicing the present invention, this is desirably a high molecular weight polyalkylene glycol such as is sold commercially under the trade name UCON Lubricant 50-I-IB-55 manufactured and sold by Union Carbide Chemical Company, South Charleston, West Virginia.

The particular sizing agent employed in bath 56 may be of any well known kind. Factors such as cohesiveness of a particular sizing agent to a particular glass yarn, cost, and the end use to which the processed glass yarn will be put will, obviously enter into selection. With respect to the last mentioned factor and by way of example, yarns which are to be knit would require a size having good inherent lubricity characteristics so that the yarn would flow smoothly in the knitting machine. Examples of suitable sizing agents for selected conditions are sodium alginate, polyvinyl alcohol and paraffin wax.

In accordance with the present embodiment of the invention glass yarn Y is drawn over the end of supply package and drawn through the apparatus at a preselected linear speed to be finally wound onto take-up roll 65. In the course of its movement the glass yarn is engaged by tension 16 which serves to maintain the yarn Y under a preestablished tension in the heat zone. By virtue of this arrangement twist which is inserted into the yarn by spindle 28 runs back through heater 20 and is arrested at tension 16. The actual number of turns of twist in the glass yarn between spindle 28 and tension 16 is, of course, controlled by the speed of rotation of said spindle 28 and the linear speed of the yarn through the spindle 28. Further, it will be clear that after the yarn is heated in its twisted state in the zone of heater 20 the yarn is cooled in the cooling zone between heater 20 and twist trapping device 46 to thereby set the twist in the glass yarn. Moreover, this yarn is lubricated in the cooling zone by roller 30 prior to passing around twist trapping device 46. This lubrication of the yarn is advantageous in facilitating the movement of the glass yarn around the twist trapping device 46 and upwardly through guide 48. Due to the fact that the yarn is wrapped about twist trapping device 46 on a small radius of curvature (twist trapping devices commonly employed in apparatus as exemplified herein being in the order of A3 inch diameter) and further, in the light of the fact that the glass yarn may rub against an adjoining wrap of yarn on the twist trapping device thereby increasing the frictional drag of the yarn by resisting its movement, the yarn has been observed to break frequently in the area of twist trapping device 46 and guide 48 in the absence of such lubrication. This lubricant also lubricates the individual filaments during the untwisting process and thereby reduces the abrasive action of filaments on each other during the untwisting step of the operation.

Upon emergence from the twist trapping device 46 the yarn is untwisted, this untwisting occurring by virtue of the operation of false twist spindle 28 in a manner well known in the art. After the yarn has been untwisted it is sized by contact with roll 51. It will be appreciated that the glass yarn, after being untwisted, is maintained under tension suflicient to prevent the afore-mentioned pigtails forming in the yarn. In the course of the movement of the yarn Y against roll 51 and through heater 60 the yarn is sized, the size fixed or dried and thus the yarn is prevented from looping. Consequently, as it is wound onto take-up roll 65 the yarn is in a substantially straight configuration, possessing only latent forces. Thereafter, the yarn from take-up roll 65 may be readily woven or knitted into a fabric after which the size is removed by washing in water or other suitable solvents or by being vaporized off in a heated zone at a suitable temperature to release or activate the latent forces in the yarn to thereby provide a product having highly desirable permanent stretch characteristics.

In fabric form the yarn either does not assume the looped or pigtail configuration because of fabric type and geometry or the loops that are developed in the yarn are never fully extended, thus barring the undesirable fracturing characteristics of the looped or pigtailed glass yarn described earlier.

The following are typical examples of the production of glass yarn processed by the method of the present invention:

Example I To produce a stretch glass yarn having high stretch and recovery characteristics for use in upholstery materials and the like, glass yarn of the type identified as Type 150/ l/O manufactured and sold by Owens-Corning Fiberglas Corporation, Ashton, Rhode Island, and having 1 turn Z twist per inch was processed by being drawn off the supply package 10 at 533 inches per minute. The yarn was S twisted 37 turns per inch by spindle 28 being operated at a speed of 19,700 rpm. and while thus being twisted the yarn was passed through heater 20 under a tension of 7 grams. The heater 20 was heated to a temperature of 1100" F., the heater being 27 inches long. UCON Lubricant SO-HB-SS was applied to the yarn by roll 30. A 0.5% solution of sodium alginate was applied to the yarn by roller 51 and the sized yarn was dried by heater 60 which was set at a temperature of 800 F. as the yarn was passed therethrough. The length of heater 60 was 27 inches. The glass yarn processed in accordance with the foregoing possessed about 400% stretch in yarn form and about in fabric form.

Example II A stretch yarn having stretch and recovery characteristics of a lower percentage than that of the foregoing example may be desired for curtains and like articles. In keeping with this objective and as a typical example thereof Type /1/0 glass yarn, of the same kind set forth in the previous example, having 1 turn Z twist was processed by being drawn 01f supply package 10 at 533 inches per minute. The yarn was S twisted 37 turns per inch by spindle 28 being operated at 19,700 rpm. and while thus being twisted the yarn was passed through heater 20 under a tension of 7 grams. The heater was 27 inches long and was heated to a temperature of 1100 F. UCON Lubricant 50HB-55 was applied to the yarn by roll 30. No sizing agent was applied to the yarn. The twisted yarn Was passed through heater 60, which was heated to 800 F. The length of the heater was 27 inches. The glass yarn produced in accordance with the foregoing procedure had about 100% stretch in yarn form and about 25% stretch in fabric form.

Thus, it will be appreciated from the foregoing that the present invention provides a method for producing stretch glass yarn having torsional forces in the yarn, which said yarn can be readily made into an article. The article exhibits permanent stretch wavy or fluffed characteristics. Moreover, the present invention provides a method for producing stretch glass yarn wherein the degress of stretch or liveliness in the yarn may be controlled as a part of the over-all process, which said stretch is uniform and permanent.

While a selected embodiment of the present invention has been herein illustrated and described, it should be apparent that many variations are possible within the scope of the present invention. For example, under certain conditions it may be desirable to provide positive feeding of the glass yarn to the take-up. This may be required, for example, when a high degree of control of the stretch in the yarn is required as in Example 11 or where the density characteristics of the yarn package are to be controlled. With such objectives in mind there is shown in FIG. 3 a modified form of the present invention. It will be appreciated, in connection with FIG. 3, that the elements below false twist spindle 28' will be identical with those shown in FIGS. 1 and 2. Moreover, it is to be understood in the modification of FIG. 3 false twist spindle 28 operates in the same manner as false twist spindle 28 of the embodiment of FIGS. 1 and 2. Thus, spindle 28 includes a blade 38' driven by an endless belt 40 against the blade by a guide pulley 42'. The spindle 28' includes an enlarged head portion 44' supporting a twist trapping device 46, and an upper guide 48'. The yarn Y' is false twisted by spindle 28' in the same manner as described in connection with the earlier embodiment whereafter the yarn is directed over guide bar 49', through guide eyes 50' and 62' and heater 60', over bar 63' to be taken up on take-up 64 driven by frictional engagement with drive roll 65. All of the foregoing elements are the same in construction and operate in the same manner as their counterparts in the embodiment of FIGS. 1 and 2. In the modification of FIG. 3 the sizing roll and trough are omitted and a pair of positively driven nip rolls or feed rolls 70', 72' are provided between bar 49' and guide 50 to nip the yarn therebetween and advance it at a controlled rate through heater 60'. Thus, the tension in the glass yarn passing through heater 60 is correlated with the heat applied to the yarn thereat so that the desired degree of relaxation in the torsional forces in the yarn is achieved. A high accurate and precise control for the yarn is, therefore, provided to control the physical characteristics of the yarn taken up on roll 65'. Obviously, the stretch imparted to the processed yarn will be a function of the degree of relaxation given the yarn as it passes through heater 60' and the temperature to which the yarn is heated at heater 60'.

Another modification within the scope of the invention is achieved with the structure of FIG. 4. Here again, the view is fragmentary and it should be understood that the arrangement of parts below false twist spindle 28" is the same as that as shown in FIGS. 1 and 2. Moreover, false twist spindle 28" includes blade 38" operated by belt 40" which is guided by pulley 42". False twist spindle 28 includes a head 44" carrying a twist trapping device 46" so that the false twist spindle operates in the same manner as that of the spindle of FIGS. 1 and 2. The yarn Y" is guided from spindle 28" over bar 49", through guides 50" and 62" to be taken up on roll 65" driven by frictional engagement with drive roll 66". It is to be understood that all of the components just recited operate in the same manner as the corresponding structures in the first described embodiment. In FIG. 4 it will be seen that a trough 54" is provided between bar 49" and guide 50". Said trough 54" is provided with a series of heating elements 74 arranged to heat a bath 56" of sizing agent having a melting point higher than ambient, such as parafiin wax. A roll 51" is partially submerged in the bath and is rotated on drive shaft 52". The yarn Y is fed against scribed earlier with reference to FIGS. 1 and 2 to control the coiling and crimping of the yarn as the yarn is taken up. It will be apparent that this modification of the in vention admits of certain additional economies in operation by avoiding the necessity for heat drying of the size.

Since certain changes may be made in the above method and apparatus without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative only, and not in a limiting sense.

What is claimed is:

1. A glass multifilament textile yarn having torsional forces set in the filaments thereof of the quantum to cause 50%80% of the length of the filaments of the yarn to assume pigtailed and crimped formations when the yarn is relaxed, said yarn having a removable size thereon which mechanically controls the said torsional forces and prevents the filaments from assuming pigtailed formations when the yarn is relaxed.

2. A glass multifilament textile yarn having controlled torsional forces set in the filaments thereof of the quantum to cause the filaments to assume crimped formations when the yarn is relaxed but insufficient to cause said filaments to assume pigtailed formations when the yarn is relaxed.

References Cited UNITED STATES PATENTS 2,914,835 12/ 1959 Slayter 281 XR 2,958,114 11/1960 Marzocchi et al 57-153 3,073,136 1/1963 Dean 57-440 3,136,110 6/1964 Searles 57-773 XR 3,309,861 3/1967 Pierson et a1 57--l40 2,230,271 2/1941 Simpson 57-140 2,230,272 2/ 1941 Slayter 57-140 2,797,529 7/ 1957 Mohr et a]. 28--72 3,080,736 3/1963 Mabru et a1 281 XR 3,201,931 8/1965 Caroselli et a1. 57-140 3,289,265 12/1966 Hodges et al 281 FOREIGN PATENTS 1,085,331 1/1955 France.

DONALD E. WATKINS, Primary Examiner.

US. Cl. X.R. 

